Our overall objective of this proposed project is to determine the nucleotide sequence of DNA from simian virus 40 and polyoma virus. The research work includes the specific cleavage of the DNA molecules of these two viruses with different restriction enzymes, and to determine the nucleotide sequence of a number of the DNA fragments from their termini. BIBLIOGRAPHIC REFERENCES: Wu, R., Jay, E. and Roychoudhury, Nucleotide Sequence Analysis of DNA, Methods in Cancer Research 12, 87-176 (1976). Wu, R., Ruben, G., Siegel, B., Jay, E., Spielman and Tu, C.D., Synchronous Digestion of SV40 DNA by Exonuclease III, Biochem. 15, 734-740, (1976).